Antitumor effect of novel anti‐podoplanin antibody NZ‐12 against malignant pleural mesothelioma in an orthotopic xenograft model

Podoplanin (aggrus) is highly expressed in several types of cancers, including malignant pleural mesothelioma (MPM). Previously, we developed a rat anti‐human podoplanin mAb, NZ‐1, and a rat–human chimeric anti‐human podoplanin antibody, NZ‐8, derived from NZ‐1, which induced antibody‐dependent cellular cytotoxicity (ADCC) and complement‐dependent cytotoxicity against podoplanin‐positive MPM cell lines. In this study, we showed the antitumor effect of NZ‐1, NZ‐8, and NZ‐12, a novel rat–human chimeric anti‐human podoplanin antibody derived from NZ‐1, in an MPM orthotopic xenograft SCID mouse model. Treatment with NZ‐1 and rat NK (CD161a⁺) cells inhibited the growth of tumors and the production of pleural effusion in NCI‐H290/PDPN or NCI‐H226 orthotopic xenograft mouse models. NZ‐8 and human natural killer (NK) (CD56⁺) cells also inhibited tumor growth and pleural effusion in MPM orthotopic xenograft mice. Furthermore, NZ‐12 induced potent ADCC mediated by human MNC, compared with either NZ‐1 or NZ‐8. Antitumor effects were observed following treatment with NZ‐12 and human NK (CD56⁺) cells in MPM orthotopic xenograft mice. In addition, combined immunotherapy using the ADCC activity of NZ‐12 mediated by human NK (CD56⁺) cells with pemetrexed, led to enhanced antitumor effects in MPM orthotopic xenograft mice. These results strongly suggest that combination therapy with podoplanin‐targeting immunotherapy using both NZ‐12 and pemetrexed might provide an efficacious therapeutic strategy for the treatment of MPM.     

Natural Antigenic Peptides from Squamous Cell Carcinoma Recognized by Autologous HLA-DR8–restricted CD4+ T Cells

A large number of human tumor antigens recognized by CD8⁺ cytotoxic T lymphocytes (CTL) have been identified. Some of them have been employed in clinical trials and have achieved some objective responses. However, little is known about those that are recognized by CD4⁺ T cells, except for a very few that were identified from melanomas. Previously, we reported that an oral squamous cell carcinoma (SCC) cell line, OSC–20, was effectively lysed by HLA-DRB1·08032 (HLA-DRS)-restricted autologous CD4⁺ T cell line, TcOSC–20. In this study, we performed two steps of chromatographic purification of the tumor cell lysate in combination with mass spectrometry. We found one reverse-phase high-performance liquid chromatography (RP-HPLC) fraction that was effectively recognized by the T cells. We analyzed the fraction by nano-liquid chromatography/electrospray ionization ion trap mass spectrometry (LC/MS/MS) and found six representative ions. We could determine the primary amino acid sequence of each of the six ions. Three of them contained a potential HLA-DR8 binding motif, and TcOSC–20 showed a rather strong cytotoxic response to one of the synthetic pep tides, namely, amino acid residues 321–336 of human a-enolase. Thus, several gene products of squamous cancer cells are endogenously processed and may be presented on HLA class II molecules, so that they could constitute target molecules for autologous CD4⁺ T cells.     

CXCL12/CXCR4 activation by cancer‐associated fibroblasts promotes integrin β1 clustering and invasiveness in gastric cancer

Cancer‐associated fibroblasts (CAFs) are reportedly involved in invasion and metastasis in several types of cancer, including gastric cancer (GC), through the stimulation of CXCL12/CXCR4 signaling. However, the mechanisms underlying these tumor‐promoting effects are not well understood, which limits the potential to develop therapeutic targets against CAF‐mediated CXCL12/CXCR4 signaling. CXCL12 expression was analyzed in resected GC tissues from 110 patients by immunohistochemistry (IHC). We established primary cultures of normal fibroblasts (NFs) and CAFs from the GC tissues and examined the functional differences between these primary fibroblasts using co‐culture assays with GC cell lines. We evaluated the efficacy of a CXCR4 antagonist (AMD3100) and a FAK inhibitor (PF‐573,228) on the invasive ability of GC cells. High CXCL12 expression levels were significantly associated with larger tumor size, increased tumor depth, lymphatic invasion and poor prognosis in GC. CXCL12/CXCR4 activation by CAFs mediated integrin β1 clustering at the cell surface and promoted the invasive ability of GC cells. Notably, AMD3100 was more efficient than PF‐573,228 at inhibiting GC cell invasion through the suppression of integrin β1/FAK signaling. These results suggest that CXCL12 derived from CAFs promotes GC cell invasion by enhancing the clustering of integrin β1 in GC cells, resulting in GC progression. Taken together, the inhibition of CXCL12/CXCR4 signaling in GC cells may be a promising therapeutic strategy against GC cell invasion.     

Evaluation of 4-hand reduction for obturator hernia with the guidance of sonography as a new treatment strategy: A retrospective study

To evaluate the effectiveness of 4-hand reduction for obturator hernia with the guidance of sonography (FROGS) as a new treatment strategy for obturator hernia. Since November 2019, FROGS was performed for all patients with obturator hernia at our emergency department. We retrospectively compared the clinical data of 20 patients who underwent FROGS (after FROGS group) to those of 23 patients who did not (before FROGS group). All patients except one were female. The male-to-female ratio, age, duration of symptoms, lesion site, and predisposing factors did not significantly differ between groups. However, the diameter of the prolapsed bowel and the body mass index of the after FROGS group were significantly larger and lower, respectively. Manual reduction was successfully performed for all 20 patients in the after FROGS group, and bowel resection was avoided for all 20 cases. However, 14 patients in the before FROGS group underwent manual reduction; of these, only one was successfully treated using a method other than FROGS, and 8 patients underwent bowel resection. There were no significant differences between groups in terms of postprocedural complications or mortality within 30 days of hernia presentation. The FROGS technique was safe and reproducible and could be used as the first choice of treatment for patients with obturator hernia.     

Association of ALDH2 Genotypes and Alcohol Intake with Dietary Patterns: The Bunkyo Health Study

Dietary habits are associated with various diseases and assessed by dietary patterns (DPs). Since the ALDH2 genotype is correlated with alcohol and several food preferences, this genotype is probably associated with DPs. In this cross-sectional study of 1612 elderly adults, we investigated the effects of the ALDH2 genotype on DPs and the mediating role of alcohol intake. We identified the ALDH2 genotype and conducted a dietary history survey, then used principal component analysis to determine DPs for each gender. We performed multiple regression analysis to determine the independent contribution of the ALDH2 genotype and alcohol intake to DP scores. We identified three DPs: the “Japanese side dish type” (DP1), the “Japanese dish with alcohol type” (DP2), and the “Western dish with alcohol type” (DP3). In men, the single nucleotide polymorphism ALDH2 rs671 was significantly associated with all DP scores. When alcohol intake was added as a covariate, ALDH2 rs671 was still significantly correlated with the DP2 score but not with the DP1 or DP3 score, and alcohol intake was significantly correlated with all DP scores. In women, ALDH2 rs671 was significantly associated with the DP2 and DP3 scores; however, after adding alcohol intake as a covariate, these associations disappeared, and alcohol intake significantly correlated with all DP scores. In conclusion, the ALDH2 genotype was associated with several DPs in elderly adults, but most associations were mediated by alcohol intake.     

Proposal for a Standard Protocol to Assess the Rheological Behavior of Thickening Products for Oropharyngeal Dysphagia

Increasing shear viscosity (ShV) in thickening products (TP) is a valid therapeutic strategy for oropharyngeal dysphagia (OD). However, salivary amylase in the oral phase and shear rate in the pharyngeal phase of swallowing can change the viscosity of TPs when swallowed. This study aims to design and validate a rheological protocol to reproduce the oral and pharyngeal factors that affect the therapeutic effect of TPs and report the viscosity measurements in a standardized scientific and precise manner. We measured (a) the variability of the ShV measurements across several laboratories; (b) the in vitro and ex vivo properties of TPs and (c) the impact of the X-ray contrast Omnipaque, temperature and resting time on the rheological properties of TPs. A common protocol was applied in four international laboratories to assess five ShV values (100, 200, 400, 800 and 1600 mPa·s) for the xanthan-gum TP Tsururinko Quickly (TQ). The protocol included the dose (g/100 mL water), stirring procedure and standing time before measurement. Each value was characterized at the shear rate of 50 and 300 s⁻¹ pre- and post-oral incubation in eight volunteers. The effect of temperature, standing time and Omnipaque was assessed. The main results of the study were: (a) The mean intra-laboratory variability on the ShV at all levels was very low: 0.85%. The mean inter-laboratory variability was higher: 9.3%; (b) The shear thinning of TQ at 300 s⁻¹ was 75–80%. Increasing the temperature or standing time did not affect the ShV, and oral amylase caused a small decrease; (c) Omnipaque slightly decreased the dose of TP and hardly affected the amylase resistance or shear thinning. This study showed that different laboratories can obtain very accurate and similar ShV measurements using this protocol which uses scientific, universal SI units (mPa·s). Our protocol accurately reproduces oral and pharyngeal factors affecting the therapeutic effect of TPs. The addition of X-ray contrast did not produce significant changes.     

Genomic determinants impacting the clinical outcome of mogamulizumab treatment for adult T-cell leukemia/lymphoma

In order to identify genomic biomarkers for the outcome of mogamulizumab-containing treatment, an integrated molecular analysis of adult T-cell leukemia/lymphoma (ATL) was conducted on 64 mogamulizumab-naïve patients. Among driver genes, CCR4 and CCR7 alterations were observed in 22% and 11% of the patients, respectively, both consisting of single nucleotide variants (SNV)/insertion-deletions (indels) in the C-terminus. Patients with CCR4 alterations or without CCR7 alterations exhibited a more favorable clinical response (complete response [CR] rate 93%, 13/14; P=0.024, and CR rate 71%, 40/56; P=0.036, respectively). Additionally, TP53, CD28, and CD274 alterations were identified in 35%, 16%, and 10% of the patients, respectively. TP53 alterations included SNV/indels or copy number variations (CNV) such as homozygous deletion; CD28 alterations included SNV, CNV such as amplification, or fusion; CD274 alterations included CNV such as amplification, or structural variants. Univariate analysis revealed that TP53, CD28 or CD274 alterations were associated with worse overall survival (OS) (hazard ratio [HR]: 2.330, 95% confidence interval [CI]: 1.183-4.589; HR: 3.191, 95% CI: 1.287-7.911; HR: 3.301, 95% CI: 1.130-9.641, respectively) but that CCR4 alterations were associated with better OS (HR: 0.286, 95% CI: 0.087-0.933). Multivariate analysis indicated that in addition to performance status, TP53, CCR4 or CD274 alterations (HR: 2.467, 95% CI: 1.197-5.085; HR: 0.155, 95% CI: 0.031-0.778; HR: 14.393, 95% CI: 2.437-85.005, respectively) were independently and significantly associated with OS. The present study contributes to the establishment of precision medicine using mogamulizumab in ATL patients.     

Hypercalcemia Associated with the Ectopic Expression of 25-hydroxyvitamin D3-1α-hydroxylase in Diffuse Large B-cell Lymphoma

An 82-year-old man was transferred to our hospital due to impaired consciousness. His albumin-corrected calcium level was 14.2 mg/dL, intact parathyroid hormone (PTH) and PTH-related protein levels were reduced, and his 1,25-dihydroxyvitamin D [1,25(OH)₂VitD] level was elevated at 71.5 pg/mL. Computed tomography revealed masses on the bilateral ribs. The mass on the rib was biopsied and diagnosed as diffuse large B-cell lymphoma (DLBCL). Immunostaining of the biopsy sample with the anti-CYP27B1 antibody revealed the ectopic expression of 1α-hydroxylase in the lesion. We herein report a rare case of hypercalcemia induced by the overproduction of 1,25(OH)₂VitD in DLBCL ectopically expressing 1α-hydroxylase.     

The Impact of Antiviral Therapy for Hepatitis C Virus on the Survival of Patients after Hepatocellular Carcinoma Treatment

Objective Owing to advances in direct-acting antiviral (DAA) therapy, a considerable number of patients with hepatitis C virus (HCV)-positive hepatocellular carcinoma (HCC) are now able to achieve a sustained viral response (SVR) after curative treatment of HCC. However, the beneficial effect of a DAA-SVR on the survival remains unclear. Methods A total of 205 patients with HCC who were HCV-positive with Child-Pugh A at the onset from 2008 to 2018 were categorized into 2 groups: 140 patients untreated for HCV throughout the entire course after HCC development (untreated group) and 65 patients treated for HCV with DAAs following HCC treatment who achieved an SVR (SVR group). After propensity score matching, 63 patients from each group were selected. Using these patients, the survival and maintenance of Child-Pugh A after HCC treatment were compared between the untreated group and SVR group. Results There was a significant difference in the overall survival (p<0.001) and the rate of maintaining Child-Pugh A (p<0.001) between the groups. The 5-year survival rates were 96% (SVR group) and 60% (untreated group), and the proportions of patients with Child-Pugh A at 5 years after HCC treatment were 96% (SVR group) and 38% (untreated group). Conclusion In patients with HCV-positive HCC, achieving a DAA-SVR after HCC treatment significantly improved the overall survival rate compared with HCV-untreated patients. The contribution of DAA-SVR during the course of HCC treatment to a longer survival is mainly due to the prevention of the progression of Child-Pugh A to B/C. Further research is needed to determine whether aggressive antiviral therapy is also effective for HCC patients with Child-Pugh B/C.